In this paper, we propose a cost-efficient single mode fiber-free space optics (SMF-FSO) based hybrid \(32 \times 2~\text{Gbps}\) wavelength division multiplexed passive optical network (WDM-PON) employing optical frequency comb (OFC) source and polarization multiplexing. OFC source is realized at optical line terminal (OLT) by modulating a single continuous wave (CW) laser source with radio frequency (RF) sinusoidal signal and dual-drive Mach–Zehnder modulator (DD-MZM). 16 coherent optical carriers are used to split into 32 x and y-orthogonal polarization states which are used to transmit the on-off keying (OOK) data of 32 channels to remotely located optical network units (ONUs). The performance of the channels is analyzed with bit error rate (BER) plots employing Gamma–Gamma (GG) FSO channel model at different turbulence regimes and lengths of FSO link. Moreover, the effect of varying the polarization mode dispersion (PMD) on BER is also evaluated. The cost of the proposed architecture is analyzed and compared with conventional PON architecture. The cost efficiency of the proposed architecture is demonstrated by the use of a single CW laser source to transmit the data of 32 users between remote node (RN) and ONUs through FSO links having reduced installation and maintenance costs.

在本文中，我们提出了一种基于成本效益的单模无光纤空间光学（SMF-FSO）的混合\（32 \ times 2〜\ text {Gbps} \）波分复用无源光网络（WDM-PON），采用光频梳（OFC）源和偏振复用。通过使用射频（RF）正弦信号和双驱动马赫曾德尔调制器（DD-MZM）调制单个连续波（CW）激光源，可以在光线路终端（OLT）上实现OFC源。16个相干光载波用于拆分为32个x和y正交偏振态，用于将32个通道的开关键控（OOK）数据传输到远程光网络单元（ONU）。使用Gamma–Gamma（GG）FSO信道模型，在不同的湍流状态和FSO链路长度下，利用误码率（BER）图分析信道的性能。此外，还评估了改变偏振模色散（PMD）对BER的影响。分析了所提出的体系结构的成本，并将其与常规的PON体系结构进行了比较。通过使用单个CW激光源通过FSO链路在远程节点（RN）和ONU之间传输32个用户的数据，降低了安装和维护成本，证明了所建议体系结构的成本效率。